Internal fluctuations effects on Fisher waves - art. no. 238303

We study the diffusion-limited reaction A + A <-> A in various spatial dime nsions to observe the effect of internal fluctuations on the interface betw een stable and unstable phases, We find that, similar to what has been obse rved in d = 1 dimensions. internal fluctuations modify the mean-field predi ctions for this process, which is given by Fisher's reaction-diffusion equa tion. In d > 1 the front displays local fluctuations perpendicular to the d irection of motion which, with a proper definition of the interface, can be fully described within the Kardar-Parisi-Zhang (KPZ) universality class. T his clarifies the apparent discrepancies with KPZ predictions reported rece ntly.